Encased steel building block

ABSTRACT

A building block formed with a core comprising compressed or crushed old automobile bodies and a coating of concrete. A process and apparatus for the preparation of old automobile bodies.

Unlted States Patent 1 ,68 ,244 Palmer 14 1 Aug. 22, 1972 [54] ENCASED STEEL BUILDING BLOCK 1,382,095 6/ 1921 Lambertw, ..52/725 72 Inventor; Robert A Palmer, D m N Y 2,097,342 10/1937 Rehfeld ..61/ 3 2,344,206 3/ 1944 Foml ..52/125 X [73] Asslgneez Korblock Corporation, Homell, 2,932 244 4/ 1960 Moyer 100/39 N.Y. [22] Filed: Aug 31, 1965 FOREIGN PATENTS OR APPLICATIONS NO: Canada Primary Examiner-Alfred C. Perham U-S. Cl. Attorney cha rles and Stonebrake &

52/600, 52/DlG. 9, 61/4 Shepard [51] Int. Cl ..E04bl/04, E04b 1/54 [58] Field of Search ..52/592, 594, 600-602, [57] ABSTRACT 1 3 4 37; 29 403 A building block formed with a core compnsing compressed or crushed old automobile bodies and a coat- [56] References Cited ing of concrete- UNITED STATES PATENTS A proeess and apparatus for the preparation of old automobfle bodles. 751,089 2/ 1904 Malette ..52/600 X 925,204 6/ 1909 Liljencrantz. ..52/600 X 4 Claims, Drawing Figures -1 I Fie- "1 67*. 157 \e :2: J I I I L 133 @1 PATENTED M1622 I972 SHEET 2 [IF 5 FIG.

FIG.

IPIATENTEU 22 1912 mm 3 [IF 5 HlllHlllll 1lll ENCASED STEEL BUILDING BLOCK This invention relates to building blocks for building various types of structures, such as walls of buildings, abutments and piers of bridges, retaining walls for earth, or other structures, and relates more particularly to such building blocks mainly of steel encased in suitable enveloping material such as concrete or cement.

An object of the invention is the provision of a generally improved and more satisfactory building block of this nature.

Another object is the provision of a simple and economical process and apparatus for making such building blocks.

' Still another object is the provision of a building block so designed and constructed that it serves the dual purpose of providing a durable and sturdy heavyduty building element for construction purposes, and at the same time an efficient means for using up otherwise unwanted waste material of unattractive appearance, thereby helping to rid the countryside of eyesores.

More specifically, an important object of the invention is the provision of a practical building block in which the main structural element is formed of compressed or crushed automobile bodies suitably encased in cement or concrete or the like, so that the use of these building blocks will help to dispose of junk automobile bodies which are a serious esthetic nuisance in many parts of the country, and'at the same time will provide a satisfactory building element for heavy duty construction purposes.

Another object is the provision of a practical and economical method for using up old or junk automobile bodies in the construction of building blocks.

These and other desirable objects may be attained in the manner disclosed as an illustrative embodiment of the invention in the following description and in the accompanying drawings forming a part hereof, in which:

FIG. 1 is a top plan view of a building block in accordance with a preferred embodiment of the present invention;

FIG. 2 is a perspective view of the same;

FIG. 3 is an end view of the same;

FIG. 4 is a vertical section taken approximately on the line 44 of FIG. 3;

FIG. 5 is a perspective view of the metallic core of the building block before it is encased in the concrete or other encasing material;

FIG. 6 is a schematic side view of the metallic core in a mold, ready to have the encasing material poured into' the mold;

FIG. 7 is an end view of the same;

FIG. 8 is a plan of a different form of building block, cylindrical rather than rectangular, suitable'for use in constructing columns;

FIG. 9 is a vertical section taken approximately on the line 9-9 of FIG. 8;

FIG. 10 is a perspective view of a metallic core element used in the construction of the block of FIGS. 8 and 9;

FIG. 11 is a schematic view partly in vertical longitudinal section and partly in side elevation, illustrating a portion of the apparatus used in manufacturing the building blocks of the present invention;

FIG. 12 is a similar view of another portion of the apparatus, constituting in effect a rightward continuation of FIG. 1 l;

FIG. 13 is a schematic crosssection through the apparatus approximately on the line 13-13 of FIG. 11;

FIG. 14 is a detail showinga hinge joint used in the apparatus, and the means for operating it; and

FIG. 15 is a somewhat schematic end elevation of a portion of the apparatus shown in FIG. 12, with parts broken away and parts in vertical section.

.The present invention includes the manufacture of building blocks or construction blocks formed basically from a steel core or body of crinkled or crumpled and compressed sheet steel and other light steel sections, encased in and firmly bonded to an outer covering of cementitious material such as concrete, and the invention also includes an economical and efficient method for manufacturing such building blocks, and comparatively simple, efficient, and inexpensive apparatus for manufacturing the blocks and carrying out the method. The invention has a two-fold purpose of, first, providing an extremely rugged and strong building block which can be used for heavy duty construction and which is of sufficient size so that a comparatively few blocks handled by power machinery will serve to complete a given foundation, abutment, pier, retaining wall, or other piece of heavy construction which would otherwise take a great many blocks of the smaller conventional kind; and second, to provide a practical means for using up discarded or junk automobile bodies, thus helping to rid the countryside of the eyesore which now exists in many places where such bodies are stored.

According to the invention, an automobile body is first stripped of the heavy metal parts, such as the engine block and accessories mounted on the engine, the transmission, the differential and other rear end parts, and the axles and wheels. This stripping operation is comparatively easy, and the articles removed have some resale value, either as replacement parts for repairing old automobiles of the same model, or as scrap iron in the manufacture of steel. As distinguished from these removed parts, the remainder of the automobile, that is, the body shell itself, has substantially no value as scrap iron unless absolutely all non-steel parts are first removed at prohibitive labor expense, and for that reason there has been, in the past, no financial incentive to make a suitable disposition of the body shell. It is these automobile body shells, lying around open storage fields and junk yards by the thousands, which have produced such an unsightly condition widespread throughout the land, a condition which the present invention aims to alleviate.-

According to this phase of the invention, the stripped automobile body, schematically shown at 31 in FIG. 11, is placed on the conveyor schematically shown at 33. This conveyor travels rightwardly when viewed as in FIG. 11, and the movement of the conveyor moves one body after another successively into one end of a high temperature tunnel oven having walls 35 and a top 37 of refractory brickwork, capable of withstanding great heat. In the specific form shown in FIGS. 11 and 13, the tunnel oven has an arched top 37, but this is shown merely as a convenient example. The details of construction of the oven, and likewise of the conveyor, are not important for purposes of the present invention, and can be varied as desired by the oven manufacturer, so long as the oven is sufficiently large in cross section to accommodate a typical automobile body as indicated in FIG. 13, and sufficiently long so that several such bodies may be in the oven at the same time, as indicated in FIG. 11.

To conserve heat, the ends of the tunnel oven are closed by an entrance door 41 and an exit door 43, each movable vertically along guideways and counterweighted by counter weights 45 and 47, respectively, which balance most of the weight of the door, leaving only a relatively small weight to be lifted when the door is to be opened. The doors, like the other walls of the oven, are made mainly of refractory brick, although any suitable conventional framework of high melting point steel alloy may be used to hold the brick in place and to permit the entire door to be raised and lowered along the guideways 48 and 49, respectively.

Near the exit end of the oven (the right-hand end as shown in FIG. 11) provision is made for introducing suitable fuel through one or more nozzles 51 in one or both of the lateral walls 35. The fuel may be either gas or oil or a combination of both, in any event being a fuel which will produce an intense hot flame for heating the oven to a very high degree, preferably about 1,100 Fahrenheit in the vicinity of the fuel nozzle 51.

Near the entrance end of the oven (the left-hand end when viewed as in FIG. 11) the tunnel has a duct 61, equipped with a high speed exhaust fan 63 driven by an electric motor 65. Baffles 67 in the duct 61 help to prevent the direct heat from coming in contact with and damaging the fan 63, without interferring appreciably with the flow of the hot air and hot gasses. This duct 61 with the exhaust fan may be placed in any desired location, extending laterally from one of the side walls of the oven, or upwardly from the roof, the latter location being illustrated in FIGS. 11 and 13 merely as an example. The motor 65 is preferably offset from the duct 61 to a sufficient distance to minimize any damage to the motor frame the hot gasses flowing through the duct 61. If the duct extends upwardly from the roof, a supplementary baffle 69 of refractory brick or other refractory material is placed above the roof 37 of the oven and below the motor 65, to reduce the possibility that radiant heat from the roof of the oven will adversely affect the motor.

The doors 41 and 43 are raised as required, in order to permit the automobile bodies to enter and leave the oven. The raising of the doors can be done in any convenient way, the details of which are not important for purposes of the present invention. For example, each door may have, at its bottom corners (at each side of the oven) a roller 71, engaged by respective cam members 73 (one at each side of the oven) which may be placed on the same conveyor 33 on which the automobile bodies are placed, or, more conveniently, on separate conveyors 75 (FIG. 15) one located at each side of the main conveyor 33. The advantage of this is that the conveyors 75 for operating the earns 73 for opening the doors may be driven and controlled independently from the main conveyor 33. For example, when one automobile body reaches a position just in front of the entrance door 41, as seen near the left end of FIG. 11, the main conveyor 33 carrying the automobile bodies may be temporarily stopped, and the conveyors 75 carrying the door opening earns 73 may be driven forward so that the cams 73 will lift the rollers 71 at the bottom corners of the entrance door 41,

thereby lifting the door to the required height. Then the cam-conveyor may be stopped and the main conveyor 33 may be driven forwardly to pass the automobile body into the oven, after which a slight additional forward movement of the cam conveyor advances the cams 73 so that the rollers 71 drop off these cams and the door closes downwardly, by gravity. A similar operation takes place when the door 43 at the exit end of the oven is to be opened. Preferably the earns 73 are so spaced with respect to each other that they operate approximately simultaneously on both doors, so that both doors are opened at substantially the same time, then the main conveyor 33 is operated to move the last body out of the oven and a fresh body into the opposite end of the oven, and both doors are closed again.

The described mechanism for operating the doors of the oven is disclosed only as a convenient example, since the details of oven door operation are not important to the rest of the invention, and may be widely varied. For example, the oven doors may be operated by electric motors, controlled by manual switches, or by automatic switches operated by suitable cams on the conveyors.

As above mentioned, the temperature produced by the fuel in the oven is preferably in the neighborhood of l,lO0 Fahrenheit, and the operation of the exhaust fan 63 will pull the hot gasses leftwardly toward the entrance end of the oven, so that substantially the entire length of the oven is heated to the high heat mentioned, there being only a slight drop in temperature from the exit end toward the entrance end of the tunnel oven. Ventilation openings are maintained near the exit end, to allow flow of air inwardly when the exhaust fan isin operation, to produce a flow of the heated gasses. This may be done by providing special air inlet openings, or preferably by having the exit door 43 open a few inches at its bottom, as shown in FIG. 11, even when it is in closed position.

Because of the resulting flow of hot gases, all of the bodies within the oven at any given time (preferably about four or five automobile bodies) are heated to the high temperature mentioned. This burns out of the bodies all of the combustible materials, such as any upholstery, and any dust, scraps I of wood or other foreign substances, and leaves nothing but the metal from which the body was made, by the time the body reaches the exit end of the tunnel. The time that any given body is within the tunnel may be varied as desired, depending on the length of the tunnel and the rate at which fresh bodies are introduced into the inlet end. Ordinarily it is found that a time within the tunnel of about one half hour, at the temperature above indicated, is sufficient for burning out all upholstery and other non-metallic materials, leaving only the burned out metal parts. These metal parts will be mainly of sheet steel, with possibly some other steel parts of relatively light cross section, such as angle braces, small channels, rods, angle irons, etc., it being remembered that the heavy metal parts such as engine, transmission, rear end elements, etc., having already been removed as above mentioned, before the body was placed on the conveyor 33 to go into the oven. The body may include some chromium plated or nickel plated parts, and minor parts of brass or other non-ferrous metals, which are of no disadvantage for purposes of the present invention but would be fatal to the satisfactory use of the body as scrap iron in the manufacture of steel.

When the burned out body comes out of the oven, the main conveyor 33 transfers it to another conveyor 81 of somewhat different construction, as seen in FIG. 12. This conveyor 81, formed for example of chains passing over suitable guide rollers 83, has a series of low lugs 85, and a series of higher lugs 87 interspersed with the lower lugs 85. The lugs 87 may conveniently be of two sections hinged as shown more particularly in FIG. 14, having an upper part 87a and a lower part 87b connected to each other by a hinge 89. A heavy duty pin 91 mounted for upward and downward longitudinal sliding motion in the lower lug part 87, and pressed upwardly by a spring 93, enters a cavity 95 in the upper lug section 87a. When it is seated in the cavity 95, this pin holds the two lug portions 87a and 87b rigidly in line with each other. However, when the pin 91 is withdrawn downwardly against the force of the spring 93, the upper lug section 87a may then swing backwardly on its hinge 89, as shown in dotted lines in FIG. 14. To withdraw the pin, there may be a cam 97 operating on a lateral projection 99 projecting from the pin 91 through a slot 101 at the side of the lowerlug portion 87 b, so that when the forward motion of the conveyor brings the lug 87 past the cam 97, the cam withdraws the pin 91 and permits the upper part 87a of the lug to swing back relative to the lower part 87b.

The cam 97 is located near the top of the steep inclined part of the conveyor 81, so that when the burned-out body is near the top of the incline, the pin 91 is withdrawn, allowing the upper section 87a of the retainer lug to swing back, while the fixed lower section 87b prevents the vehicle body from sliding down the incline. Since this section 87b is quite low, way below the center of gravity of the body, the vehicle body rolls over the fixed retainer or lug 87b. If the body attempts to slide down the incline after clearing the lug 87b, it engages the next low fixed lug 85, which once more prevents sliding and requires the body to tip over. Any desired number of such fixed lugs 85 (that is, lugs fixed to but moving along with-the conveyor) may be used between successive jointed or hinged retaining lugs, and of course the steeply inclined part of the conveyor may be made of any desired length. Finally, near the bottom of the steep incline, after the vehicle body has rolled over at least once and preferably two or three times, it comes to rest against another upright lug or retainer, which this time carries the vehicle body all the way to the top of the incline and onto the horizontal part of the conveyor, as shown near the top of FIG. 12. Meanwhile, however, the vehicle body has rolled over at least once and preferably more than once, and this tumbling action serves to shake out any residue of ash from the components which were burned in the oven, and any small fragments or pieces of non-combustible material which may be loose within the body.

The desired result of releasing the body near the top of the steep incline, for the rolling or tumbling action, at one time, and yet not releasing it when it subsequently comes up the incline, may be produced in various ways. For example, all of the high retaining lugs (sufficiently high to prevent the body from rolling over) may be of the hinged kind shown in FIG. 14, but the cam 97 which releases the hinge may be moved to an ineffective position whenever the operator finds that the vehicle has had enough tumbling action and should now continue its journey up to the horizontal part of the conveyor. Or again, hinged or jointed retainers of the kind described in connection with FIG. 14, can alternate with fixed retainers sufficiently high to prevent the body from rolling. These would be in addition to the intermediate low lugs which are to catch the body and cause it to. roll over rather than to slide down the incline. Thus, for example, a vehicle body may travel up the steep incline while resting against one of the hinged retainers 87 which hinged retainer is released as the vehicle reaches the top of the incline. Then the vehicle body rolls down the incline, hitting each of the low lugs 85 as it goes, until-it comes to rest against high retaining lugs similar to 87 but which are not hinged or jointed, and which are always in an upright position (fixed to and traveling with the conveyor) sufficiently high to prevent the body from rolling any further. These carry the body all the way up the incline and onto the flat top part. Then the next body on the conveyor is held by a high jointed retainer 87 released at the top of the incline, and rolls back to the next non-jointed high retainer, and so on, one after another.

On the upper horizontal part of the conveyor 81, is a weighing platform indicated schematically at 111, where the burned-out body can be weighed while the conveyor is temporarily stopped, or the weighing platform may be at one side of the conveyor and the auto body may be pulled or shoved laterally off of the con-- veyor onto the weighing platform and the flat working platform around the weighing scale. For making the crushed steel core for a given size and style of building block, it is desirable to use an approximately uniform weight of steel to be crushed. Since a supply of junk automobile bodies used in an operation of this kind will represent bodies of different styles, sizes, and weights, it is desirable to bring the mass of steel to an approximately uniform weight required for the particular core to be made, before the pressing operation. Moreover, most auto bodies are too large to make the core for a single building block, and must be sectioned or cut apart to make two, three, or four large sections (depending on the size of the auto body) each suitable for crumpling and compressing to a single core unit. This is why the body is weighed at this point. Attendants with cutting torches, or power driven metal saws, or both, will be stationed at the weighing location, and when the body is weighed, it can be determined into how many sections or large pieces the body should be cut. Then each of these sections is weighed again, and if too heavy, some of the most accessible parts will be cut off and laid aside, to bring the section down to approximately the required weight. On the other hand, if the section is lighter than desired, some of the spare metal cut off of other sections is thrown in, to bring it up to the desired weight. According to the invention, each metallic core used in the building block will be made from approximately one-half to one-quarter of a complete burned-out automobile body, but with some parts possibly cut off or some metal possibly added, as above explained, after the initial sectioning of the auto body, to bring the mass to an approximately uniform weight.

When the necessary weight adjustment has been made at or in the vicinity of the weighing scale 111, each adjusted section is advanced by a hydraulic ram or other suitable power mechanism to a pit type of heavy duty press, the top of which is at preferably the same elevation as the top horizontal part of the conveyor 81 and the working platform around the weighing scale. The pit of the press is indicated schematically at 113. Heavy duty pit presses capable of crushing an entire automobile body or a large section thereof into a relatively small compact mass of metal, are well known in the metal working field. Any conventional press of this kind may be used, the details of which are not important for purposes of the present invention, so are not here illustrated. Likewise conventional equipment, not here illustrated, may .be used for handling the vehicle body and each section thereof, placing it in the pit press, and removing the resulting crumpled compressed block or mass from the press when the pressing operation is completed. By the time a body reaches the weighing scale 111 and the working platform near the scale, it will have cooled considerably from the temperature which it had when leaving the burn-out oven, but will still be quite hot, and modern metal-handling equipment of conventional kind is capable of handling the hot metal parts without difficulty.

As a result of the pressing operation, the vehicle body or individual section thereof is reduced to a compact mass, mainly of sheet steel which may be described as crumpled, crimped, or crinkled. The general shape of the compact mass or block is rectangular, but with certain variations from the shape of a strict rectangular parallelepiped as mentioned below. The exact shape produced will depend on the shape of the pressing dies used in the press, and these are shaped to produce a block or mass having the shape characteristics further mentioned below. But regardless of the general exterior shape, each of the outer faces of the compressed mass will have minor irregularities and will have a multiplicity of crevices, cracks, or small openings, much like the outer surface of a ball of paper which has been crumpled or crinkled in the hands.

The compacted crinkled mass mainly of sheet steel, indicated at 121, then travels down a conveyor 123 to the elevation of the burn-out oven, and the conveyor then goes along a tunnel 125 made of refractory walls 127, along one side of the oven. Enough heat radiates from the hot walls of the oven to keep the interior of the tunnel 125 at an elevated temperature so that, at the time the crumpled mass of metal is delivered to the coating apparatus, it has a temperature in the neighborhood of 130 Fahrenheit.

The tunnel 125 continues along the side of the bumout oven to a point near the entrance end of the oven, where the hot mass 121 is delivered to apparatus for applying a coating of cement around all'sides of the metal mass, to encase the metal mass and provide a building block of definite predetermined external dimensions notwithstanding any slight variations in dimensions of the crumpled metal core. When speaking of a cement coating, the word cement is intended in a broad generic sense, as including a coating of plain or neat Portland cement or similar material, or a coating made of a mixture of such cement with a fine aggregate such as sand, or with a coarse aggregate such as gravel or crushed stone, with or without fine aggregate. Such a mixture of Portland cement and aggregate is often referred to as concrete, but is here intended to be included under the broad generic word cement.

In order to apply the cement coating, the metallic core 121 is placed in a mold open at the top but closed at sides and bottom, the mold being of the internaldimensions required to produce a building block of the desired external shape and size. The metal mass is, of course, spaced from the bottom and sides of the mold, to allow space for forming the cement coating of the required thickness. One form of such a mold is shown at 131 in FIGS. 6 and 7. The metal mass l21'therein is placed so that it is spaced from the side walls of the mold, as shown, and is elevated above the bottom wall of the mold by temporary legs or stilts 133 which may conveniently be screwed into socket members 135 which have a sufficient area so that the weight of the metal core resting on the members 135 will prevent them from tipping over.

The cement mixture, in plastic or semi-plastic condition, is then poured into the mold 131 around the metallic core 121, and tamped down sufficiently so that it flows under the metal core and fills the space beneath it, as well as filling the spaces at the sides of the metal core. Also, sufi'rcient cement is put in to cover the top of the metal core, and suitable movable mold parts (not shown) may be employed to produce upstanding flanges of cement along the upper lateral edges of the molded block and along the vertical edges at one end thereof, to produce the preferred shape further described below. These flanges, originally molded at the top, will be at the bottom of the completed building block when it is ready for use, since the block is preferably molded in an upsidedown position, although of course it may be formed in any other position desired.

Because of the plastic nature of the cement at the time it is-first applied to the crumpled metal core, the cement will penetrate into and interlock thoroughly with the crevices which exist on all faces of the metal core, as a result of the crumpling or crinkling action produced by the press. The cement will also accommodate itself to and interlock with the minor irregularities on the surfaces of the metal core, of course. Thus a particularly strong bond between the cement coating and the metal core is achieved, especially because of the multitude of irregular crevices in the metal.

Also, the fact that the metal core is hot at the time the cement is applied thereto, at a temperature of approximately Fahrenheit, helps the quick drying and hardening of the portions of the cement coating which are next to the metal core. The application of the mass of wet cement, at room temperature, to the heated metal core, will immediately tend to lower the temperature of the surface portions of the metal core, but the heat from the interior portions of the metal core immediately begins to flow toward the outer surfaces thereof and warms them up again. Thus the cement sets or hardens around the metal core in a very satisfactory manner, and is intimately and firmly bonded thereto. With the metal at about 130, the cement sets solidly and very satisfactorily, without the cracks which would develop if the metal were much hotter than l30 at the time the cement is applied.

It should be noted that minor variations in the dimensions of the metal core as it comes from the press, are taken up by slight variations in thickness of the cement coating, the outside finished dimensions of the cement being, however, standardized so as to be of predetermined exact dimensions in the completed article. But in any event, regardless of such minor variations in size of the core, the finished block in all cases is made mainly of the crumpled metal core, and the thickness of the cement coating on any face of the core, in a direction perpendicular to the face of the core, is considerably less than the thickness of the core itself in the same direction.

As already indicated, the finished building blocks may be of any desired shape and size. The most convenient shape for general utility construction (for making piers, abutments, retaining walls, and heavy-duty walls of buildings) is in the general shape of a rectangular parallelepiped the main bodyof which is shown at 141 in FIGS. 1-3, but which preferably has flanges 143 projecting beyond the bottom edge and 145 projecting beyond one end edge of the block, on each of two opposite sides or faces thereof, with rabbet grooves 147 and 149, respectively, along the opposite edges of the same face. These rabbet grooves are matched in size to the projecting flanges 143 and 145, so that when a series of similar blocks are laid to form a wall, the projecting flanges 145 at one end of a block will fit reasonably snugly, but with some play, into the rabbet grooves 149 of the next adjacent block, in the same horizontal row, and the downwardly projecting flanges 143 will fit reasonably snugly, but with some play, into the rabbet grooves 147 at the top edges of the blocks in the course or row immediately below. Preferably a strong adhesive, such as epoxy resin, is spread in the rabbet grooves of one block before the next adjacent block is laid, so that the epoxy resin practically unites the various blocks to each other to form a coherent unified mass. If desired, the inner edges of the projecting flanges 143 and 145 may be slightly chamfered as shown at 151 in FIG. 3, to assist in guiding one block against the next adjacent block already laid. Because the joints between adjacent blocks are sealed by epoxy resin rather than by cement mortar, a wall or other structure of pre-formed blocks of this kind can be built safely in sub-freezing weather without special heating precautions as required when doing cement or concrete construction in cold weather.

Although the blocks may be of any desired size, it is contemplated that in general the blocks will be considerably larger and heavier than common conventional building blocks such as the usual concrete building blocks. They will ordinarily need to be handled by mechanical handling means, such'as small cranes or hoists. Tongs of the kind often used for handling large pieces of stone can be employed for grabbing the building blocks and hoisting them into place. It is convenient, however, to provide a special lifting element on each block which may be engaged by a hook on a hoist, thus eliminating the need for tongs.

The lifting element is conveniently provided by having a cavity in the cement coating of the top face of the building block, and burying a metallic handling element with its ends in the cement coating, and with a central portion accessible in the cavity, so that it may be hooked onto a lifting hook. The metallic lifting element may be either straight or of any other desired shape. In the form shown in FIGS. 1, 4, 5, and 6, the lifting element is a metal rod bent into a loop and having ends 157 extending straight and approximately tangentially to the loop 155. The ends 157 are buried in the cement coating on the top of the block, while there is a cavity 159 around the loop 155, so that the loop is exposed and can be engaged by a lifting hook. The cavity is conveniently formed by placing a tube 161 in the mold 131, as seen in FIG. 6, and resting the lifting element 155, 157 on the top of this tube before the crumpled metal core 121 is placed in the mold 131. Then when the cement coating is inserted in the mold, it will flow around the outside of the tube 161, which will cause a cavity to be left in the coating at this point.

After the cement has solidified enough so that the block may be handled and taken out of the mold, the

members 133 which served as legs to hold the metal core away from the bottom of themold are unscrewed from the plates or heads 135 in which they are screwed, leaving the latter within the cement coating. Then the holes left by unscrewing the legs 133 are filled with cement. There may be wrench sockets in the exposed ends of the legs 133, to facilitate the unscrewing.

While the core 121 may be of any desired shape according to the broad aspect of the invention, a specific aspect of the invention deals with the preferred shape. One feature is that the lower face of the metal core mass 121 is shaped to be slightly concave in transverse cross section, across the thickness of the block, as seen at 165 in FIGS. 3, 5, and 7 (the latter view showing the inverted position of the block during the coating operation). The purpose of this slight concave shape is to concentrate vertical pressure forces somewhat inwardly toward the center of the block, thus making the blocks stronger and capable of supporting heavier loads without tending to spread the block laterally and perhaps crack off the cement coating on the lateral faces of the block.

- Another feature in the preferred form of block is the concave grooves 167 running along the comers of the metal cor'e where the rabbet grooves 147 are located in the final block, and the concave grooves 169 running vertically along the comers of the core where the rabbet grooves 149 are located in the final block. The purpose of these grooves is to allow space for the desired minimum thickness of cement coating in the vicinity of the rabbet grooves 147 and 149. It will be seen especially from FIGS. 3 and 7 that the thickness of the crumpled metal core 121 is greater than the thickness of the finished block between the projecting flanges 143 and 145, and the top edge of the metal core 121 is at an elevation a little above the bottom faces of the rabbet grooves 147. In other words, the finished building block is mainly of compressed and crumpled metal, and the cement coatings on the faces of the metal core are comparatively thin. Consequently the grooves 167 and 169 must be formed in the metal core, in the locations where the rabbet grooves 147 and 149 are to appear in the finished article, to allow space for the desired minimum thickness of about 2% inches of cement coating in these locations.

While the preferred building block is in the general shape of a rectangmlar parallelepiped, other shapes may be used for special situations, and a cylindrical shape is particularly useful for making supporting columns for bridges or other structures. Referring to FIGS. 8-10, a typical cylindrical building block is shown in general at 181. In this case the metal core could be a single piece of compacted crumpled sheet metal of approximately cylindrical shape, but preferably is in the form of four separate segments each in the shape of a quarter of a cylinder, as shown at 183. Such a shape is easier to form in a pit press than a completely cylindrical shape. The segments 183 are placed in the mold, slightly separated from each other as shown, and the cement forms a slight separating layer between the individual segments, as well as forming a coating around the outside of the segments, as plainly seen in FIGS. 8 and 9. These segments, just like the main metal core of the rectangular block, are of crinkled or crumpled metal having a multiplicity of small crevices all over their exposed faces, so that the cement interlocks firmly with each of the metal core pieces.

For ease of lifting, the cylindrical building block preferably has a lifting element 187 with its ends embedded in the cement material at the top, and the central portion of the element 187 accessible in a central cavity 189 formed in the top face of the block. Also, the peripheral or circumferential edge of the block at the upper end preferably has a rabbet groove 191 extending all the way around the circumference, and there is a hollow cylindrical flange 193 of corresponding size projecting downwardly around the margin of the lower face of the block, so that when one block is placed on top of another to construct a column, the flange 193 of the top block extends reasonably snugly, with some play, into the groove 191 of the block im mediately below. As before, the blocks are preferably cemented to each other by epoxy resin.

Merely for the sake of typical examples of suitable dimensions, and not as a limitation upon the invention, it may be said that at present it is preferred to make the rectangular style of block with a thickness (side to side when viewed as in FIG. 3) of 2 feet, and a length (end to end in the direction of FIG. 4) of 4 feet not counting the projecting flanges 145, or 4 feet 3 inches including the projecting flanges, and with a height, top to bottom of three feet not counting the bottom projecting flanges 143, or 3 feet 3 inches including such projecting flanges. The rabbet grooves 147 and 149 are preferably a width (in a direction through the thickness of the block) of 2% inches, the other dimension (in the direction of the length of the block or the height of the block, as the case may be) being about 3 A inches. With these dimensions, the flanges on one block will fit reasonably well into the grooves of the next block, but not making a perfectly tight fit therewith, as there will be a slight crack or space between the projecting flange of one block and the bottom of the groove of the next adjacent block. Therefore the pressure, both vertical and longitudinal, will come on the main body of the building block itself, not on the projecting flange, and there will be no tendency to break the flanges off.

Typical dimensions of the compressed crumpled sheet metal core, for a block having the finished outside dimensions above mentioned, are sufficiently smaller than the outside dimensions of the finished block so that the cement coating on each face of the metal core is about 2% inches thick. The concave bottom 165 may have a radius of about 24 inches. The concave grooves 167 and 169 may each have a radius of about 2 inches.

These typical dimensions, given as an example, have the advantage that one typical conventional sedan automobile body, stripped-down and burned out as above indicated, will provide the metal to be compressed in the pit press to form two. or three metal core elements each suitable for making one building block. An unusually large auto body may be sectioned into as many as four sections, each suitable for compressing into a single core element. Of course a little metal may have to be taken away or a little added to each body section, before the pressing operation, as already indicated above. The dies used in the pit press are, of course, of the proper shape to form the metallic core into the desired shape for use in the building block.

It should be emphasized that the building blocks of the present invention are suitable for very heavy duty construction and capable of withstanding very heavy compressive loads. The pit press, wherein the auto body sections are compressed to form the individual crumpled core elements, preferably exerts a force of about 850 tons in each direction. When this is divided by the area of the largest face of the metallic core element, something less than l2 square feet, it is seen that the final compressive force exerted against this face of the core is about tons per square foot, in a direction through the thickness of the core element. The area of the top and bottom faces of the core area is something less than 8 square feet; therefore the final pressure exerted by the press on the core element in the direction which will be the vertical direction of the finished block, is somewhat more than I00 tons per square foot. This is more than the crushing strength of the concrete or other cement coating on the metal core, thus showing that the metal core itself can safely withstand all of the compressive load that can be applied to the cement coating, and showing that the finished block is suitable for heavy duty loads. As already mentioned, the concave shape of the lower face of the metal core tends to concentrate the vertical compressive load toward the center of the thickness of the material immediately below it, thus minimizing any tendency of the compressive load to spread the bottom cement facing on the block or to spread the underlying block in a direction through its thickness and to spall or crack off the lateral cement facings from the underlying block. Also, the finished building block maintains its strength indefinitely. Although the metal core is formed mainly of thin sheet steel which would gradually rust away if exposed to air, the complete encasement of the sheet steel in the cement coating serves to prevent rusting or oxidation of the metal.

It is seen from the foregoing disclosure that the objects and purposes of the invention are well fulfilled. It is to be understood that the foregoing disclosure is given by way of illustrative example only, rather than by way of limitation, and that without departing from the invention, the details may be varied within the scope of the appended claims.

What is claimed is:

l. A building block for heavy construction purposes comprising a central crumpled metallic core composed essentially of a portion of a compressed and crumpled sheet metal automobile body, encased in a coating of cement covering all exterior surfaces of said central core and interlocked therewith, said central core being of generally rectangular shape having grooves running along certain edges thereof, and said cement coating also having external grooves running along edges corresponding to the grooved edges of said core.

2. A construction as defined in claim 1, in which certain edges of said building block other than said grooved edges have flanges projecting therefrom to engage in the grooves at'edges of adjacent similar blocks when a series of such blocks are laid together to form a wall.

3. A building block for heavy construction purposes comprising a central metallic core of crumpled and compacted sheet metal, said core being of the general shape of a rectangular parallelepiped with rabbet grooves running along certain edges, and a coating of cement encasing all exterior surfaces of said metallic core, the exterior surfaces of said cement coating also being of the general shape of a rectangular parallelepiped and having rabbet grooves running along at thickness of the block, and a coating of cement encasing all exterior surfaces of said metallic core, the exterior surfacesof said cement coating also being of the general shape of a rectangular parallelepiped and having rabbet grooves running along at least-some of the edges of the coating corresponding to the-edges of the core which have rabbet grooves, said cement coating further including flanges of cement projecting from certain edges of the block which do not have rabbet grooves, said projecting flanges being adapted to fit into the rabbet grooves of adjacent blocks of similar construction when a series of such blocks are laid together to form a wall. 

1. A building block for heavy construction purposes comprising a central crumpled metallic core composed essentially of a portion of a compressed and crumpled sheet metal automobile body, encased in a coating of cement covering all exterior surfaces of said central core and interlocked therewith, said central core being of generally rectangular shape having grooves running along certain edges thereof, and said cement coating also having external grooves running along edges corresponding to the grooved edges of said core.
 2. A construction as defined in claim 1, in which certain edges of said building block other than said grooved edges have flanges projecting therefrom to engage in the grooves at edges of adjacent similar blocks when a series of such blocks are laid together to form a wall.
 3. A building block for heavy construction purposes comprising a central metallic core of crumpled and compacted sheet metal, said core being of the general shape of a rectangular parallelepiped with rabbet grooves running along certain edges, and a coating of cement encasing all exterior surfaces of said metallic core, the exterior surfaces of said cement coating also being of the general shape of a rectangular parallelepiped and having rabbet grooves running along at least some of the edges of the coating corresponding to the edges of the core which have rabbet grooves.
 4. A building block for heavy construction purposes comprising a central metallic core of crumpled and compacted sheet metal, said core being of the general shape of a rectangular parallelepiped with rabbet grooves running along certain edges and with a bottom surface slightly concave in a direction through the thickness of the block, and a coating of cement encasing all exterior surfaces of said metallic core, the exterior surfaces of said cement coating also being of the general shape of a rectangular parallelepiped and having rabbet grooves running along at least some of the edges of the coating corresponding to the edges of the core which have rabbet grooves, said cement coating further including flanges of cement projecting from certain edges of the block which do not have rabbet grooves, said projecting flanges being adapted to fit into the rabbet grooves of adjacent blocks of similar construction when a series of such blocks are laid together to form a wall. 